KABUL -- The Afghan parliament's rejection of most of President Hamid Karzai's proposed cabinet this weekend dealt him a major setback and has created more political turmoil that could last months.

The decision to veto 17 of 24 cabinet nominees was described by parliament members as an unprecedented show of power by the often-acquiescent legislative body and a rejection of Karzai's tendency to dole out top positions to powerful ethnic or political constituencies.

"This outcome was a wake-up call," said Shukria Barakzai, a parliament member from Kabul. "It means the [parliament members] are thinking differently, and they want real change in the governance of the country."

A presidential spokesman, Wahid Omar, said Karzai was "of course not happy" but will respect the decision of the parliament and plans to deliberate before choosing new nominees.

"The president was surprised by the rejections," he said. "This is not a pleasant situation."

With less than a week before the parliament is scheduled to take its six-week winter recess, Afghan and Western officials expressed concern that an extended delay in forming a new government could postpone urgently needed reforms. Some parliament members said they were willing to forgo or shorten their vacation if Karzai asks them to continue their work on the cabinet.

The head of the United Nations mission in Afghanistan, Kai Eide, told reporters on Sunday that he was surprised by the number of nominees rejected. "It's a setback, and it's a distraction," he said.

Some officials here worried that an important international conference to discuss the role of foreign nations in Afghanistan, scheduled for Jan. 28 in London, could be undermined if the country does not have a functioning government by then.

Omar, the spokesman, played down those concerns at a news conference Sunday, saying that caretaker ministers, and in some cases deputies, are able to keep the government functional.

The seven ministers confirmed by the parliament included the defense, interior and finance ministers. All but one of the seven are already in the cabinet, and they are largely supported by the United States.

Parliament members said they rejected other nominees for a range of reasons: They saw them as representatives of warlords or ethnic groups, or they lacked competence. The most prominent nominee to be voted down was Ismail Khan, a powerful commander from western Afghanistan who had served in Karzai's cabinet as the minister of water and energy.

Khalid Pashtun, a parliament member from Kandahar province, said he considered the vote on Saturday a major achievement for the parliament.

"We have said no to the politics of dividing up the power by shares," he said.

The vote also offered clear evidence of Karzai's eroding political support in the wake of a contentious election discredited by fraud. Karzai eventually won a second term by default when his opponent dropped out of the race. The U.S. government and other Western countries have pressured Karzai to fight corruption and install competent ministers.

"I know it will be difficult for Karzai. Time is short, they need a stable government, but only filling a seat is not enough. We need capable, responsible, competent ministers," Barakzai said.